Cable release mechanism

ABSTRACT

A MECHANISM FOR RELEASABLY SUPPORTING OBJECTS WHICH ARE VERTICALLY DISPOSED THEREFROM, COMPRISING A HOUSING FROM WHICH THERE DEPENDS A PLUNGER AND A RELEASABLY COUPLING. THE MECHANISM IS SUPPORTED BY THE PLUNGER WHILE THE LOWER EXTREMITY OF THE COUPLING ENGAGES THE OBJECT WHICH IS TO BE RELEASABLY SUPPORTED. THE PLUNGER IS CONNECTED TO A MANDREL BY A GROOVED CAM WHICH COOPERATES WITH A PAIR OF STEEL BALLS IN A MANNER TO CONVERT RECIPROCAL RECTILINEAR MOTION OF THE PLUNGER INTO INTERMITTENT ROTATIONAL MOTION SO AS TO CAUSE ROTATION OF THE MANDREL WHICH IN TURN IS UNSCREWED FROM THE COUPLING. INTERPOSED BETWEEN THE MANDREL AND THE GROOVED CAM IS A SECOND GROOVED CAM WHICH IS ENGAGED BY A PIN IN A MANNER TO PRODUCE AN EXTREMELY HIGH INITIAL TORQUE AFTER SEVERAL INI-   TIAL CYCLES OF RECIPROCATING RECTILINEAR MOTION IS IMPARTED INTO THE PLUNGER.

NUV. 9, 19711 R. G. WOOD CABLE RELEASE MECHANISM 2 Sheets-Sheet 1 Filed Aug. 24, 1970 US i W A T N .M LM win AC6 mm? mm y E B Q W -w 153 R. G. WOOD CABLE RELEASE MECHANISM Filed Aug. 24, 1970 I/VVE/VTOJZ RICHARD @WOOD BY MARCUS LBATES /*//S flGE/VT ,bl8,l7l Patented Nov. 9, 1971.

3,618,177 CABLE RELEASE MECHANISM Richard G. Wood, 3665 E. County Road, Apt. 5, Odessa, Tex. 79760 Filed Aug. 24, 1970, Ser. No. 66,349 Int. Cl. E211!) 31/00 US. Cl. 24-201 R 10 Claims ABSTRACT OF THE DISCLOSURE A mechanism for releasably supporting objects which are vertically disposed therefrom, comprising a housing from which there depends a plunger and a releasably coupling. The mechanism is supported by the plunger while the lower extremity of the coupling engages the object which is to be releasably supported. The plunger is connected to a mandrel by a grooved cam which cooperates with a pair of steel balls in a manner to convert reciprocal rectilinear motion of the plunger into intermittent rotational motion so as to cause rotation of the mandrel which in turn is unscrewed from the coupling. Interposed between the mandrel and the grooved cam is a second grooved cam which is engaged by a pin in a manner to produce an extremely high initial torque after several initial cycles of reciprocating rectilinear motion is imparted into the plunger.

BACKGROUND OF THE INVENTION Cable line release mechanisms are known to those skilled in the art. For example, Pat. No. 2,935,302, issued May 3, 1960, to P. Cavins exemplifies a prior art releasable tool holding socket. Fishing tools, such as exemplified by Osmnn, 2,698,763; and Long et al., 1,015,198, take on many different forms and constitute an entire field of endeavor.

A sand line is frequently used to accomplish a number of different oil well servicing operations, including swabbing, operating a sand pump, or logging. Certain potential hazards are ever present when performing these operations by using a cable for the reason that the tool may inadvertently become stuck in a manner that makes it necessary to cut or break the cable. In the latter event, the workmen must fish for and remove the lost or stuck tool. This fishing operation is greatly complicated by the presence of the broken cable which is left attached to the lost tool. It would therefore be desirable to have a mechanism which would allow the cable to be released from the tool in the event that the tool became stuck, thereby facilitating recovery of the tool as well as preventing the financial loss which results from breaking the cable.

Fishing operations are usually performed by the use of a sucker rod or other tubular goods which enable the fishing tool to be lowered into and out of a borehole in an attempt to retrieve the lost or stuck objects therefrom. A substantial time savings is achieved by fishing with a cable, as for example a sand line, which can make the trip into and out of a borehole in a fraction of the time required when using a string of sucker rod or tubing.

The fishing tool can be attached to the end of a sand line and rapidly lowered into the borehole. Upon engaging the fish with the fishing tool, a recovery attempt is made and, if it is successful, the fish is brought to the surface of the ground thereby freeing the borehole of unwanted objects.

On the other hand, if the fish is so securely lodged that the pull or tension required upon the cable exceeds the designed tensile strength, the cable will part and the fishing job becomes more complex. To prevent further complicating the recovery job, it is desirable to be able to attach a fishing tool to a sand line by a mechanism which will permit the sand line to be controllably disengaged from the fishing tool in the event the fish cannot be retrieved with the cable.

When it becomes obvious that the tensile strength of the cable is insufficient to retrieve the fish, it is desirable that the fishing tool have associated therewith means by which it can be released by manipulation of the sand line, whereupon the release mechanism can then be brought to the surface of the earth, and a sucker rod or tubing can then be used to retrieve both the stuck fish and fishing tool.

It is also desirable to have a release mechanism which can be rapidly run downhole on a sand line in order to enable objects to be placed downhole in a well by a posi tive controllable manipulation of the release mechanism. It is also desirable to have a release mechanism which is actuated in a positive predetermined manner so as to prevent inadvertent release thereof. It is further desirable to have a release mechanism which can be actuated by a wire line by simple fool-proof manipulation of the line.

SUMMARY OF THE INVENTION The present invention comprehends a release mechanism for releasably suporting fishing tools and the like in a borehole and includes an external housing which may be made into several convenient sections so as to enable disassembly thereof. A plunger reciprocatingly received within the upper marginal end of the housing has one end adapted to be afiixed to a sand line with the remaining end forming a portion of a mechanism hereinafter called a transducer, which converts reciprocal rectilinear motion into rotary motion. The plunger is actuated by manipulation of the wire line. The transducer is comprised of a grooved cam which cooperates with spaced apart guide means so as to impart rotational motion into the cam as the plunger is reciprocated. The cam drives a jack screw arrangement upon which there is disposed a second grooved cam, hereinafter called a mandrel, for imparting high initial torque into a barrel. The barrel threadedly engages a coupling. This combination of elements broadly provides a release mechanism having a plunger reciprocatingly received therein with the plunger being attached to a mandrel by a transducer which converts reciprocal motion into rotational motion so as to enable a pumping action effected upon the plunger to release a coupling member from the mechanism.

It is therefore a primary object of the present invention to provide a release mechanism which is actuated by reciprocation of a supporting member located thereon.

Another object of the present invention is the provision of a release mechanism for releasably supporting fishing tools and the like within a borehole, with the mechanism including a coupling member which is unscrewed or detached therefrom upon actuation of a sand line to which the tool is attached.

A further object of this invention is the provision of a release mechanism having a transducer therein which changes reciprocal motion of one member into rotational motion which is effected on another member so as to enable the last member to be detached from a coupling member.

A still further object of this invention is the provision of a release mechanism having a support means thereon which is attached to a cable so that when the cable is reciprocated a predetermined number of times the release mechanism will be activated so as to become disengaged from an object to which it is removably attached.

Another object of the present invention is the provision of a fishing tool accessory which produces intermittent rotational motion from reciprocating rectilinear motion, which must be actuated a predetermined number of times 3 before the releasing action commences, and which produces an initial high torque when the release action is initiated.

The above objects of the invention are attained by the provision of apparatus fabricated in a manner essentially as outlined in the above abstract and summary.

These and various other objects and advantages of the invention will become readily apparent to those skilled in the art upon reading the following detailed description and by referring to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of a part of a borehole located in the earth, which includes a side elevational view of a mechanism which diagrammatically sets forth one use of the present invention;

FIGS. 2A and 2B are longitudinal cross-sectional views of part of the apparatus seen in FIG. 1, and sets forth the essence of the present invention, with some parts thereof not being sectioned for clarity, and some other additional parts being included so as to better disclose the invention;

FIGS. 3, 4, 5, 6, 7, and 8, respectively, are cross-sectional views taken along line 33, 4-4, 55, 66, 77, and 8-8, respectively, of FIGS. 2A and 2B;

FIG. 9 is a part cross-sectional part side elevational fragmentary representation of part of the apparatus seen in the foregoing figures;

FIG. 10 is a side elevational view of part of the device seen in FIGS. 2A and 2B, with some parts thereof being broken away and shown in section for clarity; and

FIG. 11 is an idealized hypothetical illustration which is included herein for the purpose of more fully explaining the details of FIG. 10.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 discloses a release mechanism 10 which is supported from its upper extremity by sand line 11 so as to enable an object 12 which is useful downhole in an oil well to be run into or out of a borehole 13.

As more particularly disclosed in FIGS. 2A and 2B, the release mechanism includes an upper cylindrical housing 14 which is removably attached or joined to a lower housing member 15 by a hollow threaded member 16. Member 16 may be provided with seals in any usual manner if desired, so as to prevent communication of the housing interior with deleterious substances found downhole in some boreholes.

The upper extremity of the housing is closed with cap 17 through which the threaded upper marginal end portion 18 of a plunger reciprocatingly depends. A coupling member 19 is removably affixed at the lower extremity of the mechanism with the member including box 20 to which useful apparatus, such as described in conjunction with FIG. 1, may be threadedly secured.

The plunger includes a polished bearing portion 21 which diverges at shoulder 22 so as to form a downwardly depending circumferentially extending skirt member 23, with the skirt member being outwardly disposed into a flange at 24, with the flange having diametrically opposed steel balls 25 caged therein so as to enable the balls to ride within the cage in low friction engagement therewith. Stated otherwise, the steel ball is captured within a detent and inwardly depends from the inner peripheral surface of the skirt.

Member 26 threadedly engages an upper marginal portion of the plunger with seal means 27 sealing the interface between members 17 and 26. Member 26 outwardly diverges to form a boss 28 which serves several of the illustrated purposes.

The upper housing is provided with counterbores 29, 30, and 31, which diminish in bore in an upward direction. Bore 29 forms a cylinder which reciprocatingly receives flange 24 while bore 30 forms a cylinder which receives shoulder 22 and bore 31 forms a cylinder which receives the bearing surface of the plunger. All of the interengaging surfaces are machined for low friction engagement.

A splined connection is effected at 31' between the plunger and the housing by the illustrated spring loaded rod which rides in its associate grooves. Other more complex splined connections may be substituted for the rod and groove if deemed desirable.

Bore 32 defines an annulus which receives biasing means 32 therein. The biasing means is illustrated as being in the form of a spring, however it can take on any other form so long as it urges the plunger in a downward direction relative to the housing.

A grooved cam 33 in the form of a cylinder is provided with a complicated groove 34 which meanders in a particular pattern about its entire 360 outer peripheral surface area. The cam is rotationally received within the skirt member and includes a downwardly extending portion which is rotatably captured within member 16 and within which there is threadedly secured a jack screw 36 having the illustrated stop nuts 37 jammed against the lower extremity of the cam.

A mandrel 39 threadedly receives the lower end portion of the jack screw at 38 with the illustrated threads preferably being square or of the acme type. Longitudinally extending slot 40 guidably receives pin 41 therein so as to prevent rotation of the mandrel until the pin rides out of the slot. A second pin 42 engages a groove located within surface 43 of the mandrel for a purpose which will be better appreciated later on. The mandrel includes a shoulder at 44 which forms a stop member with respect to the barrel, while interface 45 of the mandrel slidably engages the illustrated wall of the housing. The outside peripheral wall surface of barrel at 47 engages the inside peripheral wall surface of the housing in low friction relationship so as to enable the member to be rotated relative to the housing.

A hollow bore 48 of the mandrel is of a suflicient size to enable the jack screw to be received therewithin. The

lower extremity of the mandrel is indicated by numeral 49. The mandrel is provided with spaced apart splines or radially disposed fins which commence at 50 and extend into proximity of end portion 49. Shoulder 51 of the barrel is abuttingly received by a complementary shoulder located on the housing, while the illustrated counterbore in the housing provides a bearing surface for the lower reduced extremity 52 of the barrel. The lower depending end of the barrel threadedly engages the before mentioned coupling member 19. Pins 53 are circumferentially disposed about and firmly afiixed to the lower extremity of the housing, and are slidably received within the coupling member in the illustrated manner of FIG. 8. I

As best illustrated in FIGS. 7 and 9, in conjunction with FIGS. 2A and 2B, the barrel 47 is provided with diametrically opposed longitudinally extending grooves 60 formed within the inside peripheral wall surface thereof, so as to slidably receive the complementary longi tudinally extending fins or splines 61 which radiate from the outside peripheral wall surface of the mandrel. Accordingly, the mandrel is slidably aflixed to the barrel by asplined connection. The uppermost boss of the mandrel is provided with a groove 43' which is adapted toreceive pin 42 therein so as to impart rotational motion into the mandrel as the mandrel completes its movement in an upward direction with respect to the housing. It should be noted that the lowermost portion 44 of the. boss is located with respect to pin 42 so as to enable the upper portion of the groove in the boss to engage pin 42 as the pin 41 rides freefrom the bottom of the slot or longitudinal groove 40. The upper'extremity of the groove 43' diverges so as to better enable the pin to be guidably received therein. p

Looking now in greater detail to the grooved cam, 33 and in particular to FIGS. 10 and 11 in conjunction with FIGS. 2A and 2B, the groove provided in the outer peripheral wall of the cam is seen to commence at diametrically opposed positions 63, 63' and vertically extend in a downward direction at 64, 64' where the grooves bottom at 65, 65' and then reverses direction to describe the sloped portion at 66, 66' where the groove at 67 has meandered 180 about the outside peripheral surface of the cam. Hence the groove 63 is identical to and diametrically opposed from the groove at 63'. Numeral 68 illustrates a downwardly sloped portion of the groove which guides the ball therealong. The groove at 65 is sloped in the particular illustrated manner to assure even transition of the ball as it travels from the vertical to the sloped portion of the groove.

OPERATION The tool in the configuration of FIG. 2 is illustrated in its operative standby condition with the spring biasing the plunger to the lowermost position and with the coupling member being threadedly secured to the lowermost portion of the barrel. Of course, as weight is applied to the coupling member, the sand line will urge the plunger to its uppermost position against the compressive force of the biasing means. With the sand line attached at 18 and a fishing tool attached to the box 20, the entire apparatus is rapidly run downhole until the tool engages a fish, assuming this action to be the purpose of running the release mechanism into the hole.

When it is desired to bring the fish out of the hole, tension is placed on the sand line, thereby placing the housing under tension and enabling the coupling to lift the fishing tool and the fish engaged therewith from the borehole, thereby accomplishing the trip into and out; of the hole in a minimum of time and with a minimum of above ground supporting equipment.

Should it be discovered that the fish is unduly stuck in the borehole, as evidenced by an undue amount of tension being imparted into the sand line, it is then necessary to release the fish along with the fishing tool by actuating the cable release mechanism. This is accomplished by cycling the sand line with a pumping-like action whereby the plunger of the tool is reciprocated upward and downward an amount sufficient to enable the steel balls 25 to travel the entire effective length of the grooved cam, that is, to ride down groove 64 to position 65, back up the sloped groove 66 to the uppermost portion of groove 63, and then back down the corresponding diametrically opposed vertical groove 64', with this action continuously taking place as the sand line is pumped. The cooperative action between the cam and the plunger causes member 33 to rotate 180 each cycle of the sand line. As member 33 rotates, jack screw 36 lifts the mandrel longitudinally of the housing and barrel, with pin 41 preventing rotation of the mandrel. As the upper surface of the mandrel reaches the pin 42 the pin is guidably received by and rides Within the slot 43 while pin 41 leaves or is disengaged from slot 40. The cooperative action of pin 41 and slot 43' imparts rotational motion into the mandrel. It will be noted that a large number of revolutions of the jack screw is required in order to engage pin 42 with the corresponding groove, and thereafter several revolutions of the screw are required in order to rotate the mandrel a portion of one revolution, and accordingly, this expedient provides a lost motion effect prior to imparting an exceedingly high torque into the mandrel. As the mandrel is lifted by the jackscrew, the splines 61 slide in an upward direction with respect to the barrel 47 until the slot 43' engages pin 42 whereupon rotation of the mandrel commences. This action causes the splines to rotate the barrel 47 thereby providing the before mentioned high torque force which is effected at the threads on the coupling member. This high torque rotational force breaks the threaded connec tion so that further rotation of the mandrel with respect to the coupling member requires a reduced force.

As the groove in the mandrel clears the pin 42, the upper face 39 of the mandrel abuts nut 37. This sequence of mechanical events places the grooved cam in direct drive with the barrel. At this stage of the operation each revolution of the grooved cam will accordingly impart one revolution into the barrel so that the coupling member is now rapidly unscrewed from the lower depending portion of the barrel. Pins 53 are slidably received within the coupling member for the purpose of preventing rotation of the member with respect to the housing there by effecting positive relative rotational motion between the coupling and the barrel. After a sufficient number of cycles of the plunger, the coupling member is unscrewed from and drops free of the housing and barrel, thereby enabling the coupling to be left downhole with the fishing tool, while the remainder of the cable release mechanism is winched to the surface. The workover crew must now enter the hole and retrieve the coupling member along with the fishing tool and the fish by utilizing apparatus having a greater tensile strength than the sand line in order to retrieve the stuck fish.

It is obvious that the cable release mechanism can be used for purposes other than fishing, as for example, setting a packer or depositing instruments downhole in the borehole. It is also considered obvious to reverse the grooved cam configuration so as to enable the coupling member to be stabbed and screwed back onto the barrel.

In order to prepare the tool for another trip, the threaded connection at 16 is broken, the mandrel repositioned on the jackscrew, and the barrel threadedly replaced within the coupling member by utilizing a tool which engages the barrel in a manner similar to the splined connection of the mandrel.

It will occur to those skilled in the art that various modifications can be effected upon the cable release mechanism of the present invention. For example, it may be desired to eliminate the lost motion connection provided by the screw jack threads between pin 42 and the upper surface of the mandrel. Furthermore, it is possible to make the mandrel an integral part of the grooved cam so as to eliminate the high torque grooved portion of the mandrel along with or without the screw-jack. The number of balls, the configuration of the grooves in both the mandrel and the cam, and the length of various components of the tool can be changed so as to effect a particular advantage for various uses of the invention.

The entire tool, when fabricated in accordance with the illustrations set forth in the drawings, presents a plunger area which closely equals the housing cross-sectional area. Accordingly, no predictible part of the tool will fail before another when the tool is placed in tension. The shoulder 44 between counterbore 47, 44 is considered necessary because of the extreme bending moment present (at 51) when the tool is in tension, and because of the necessity of a large working area in the upper mandrel portion of the housing.

Pin 41 could be eliminated because of the presence of fins 61, however its presence is considered an added safety factor since it assures alignment of pin 42 with its groove.

I claim:

1. A release mechanism for vertically supporting objects comprising a housing; a plunger, means by which said plunger is reciprocatingly journaled to said housing, support means on said plunger for supporting the release mechanism; a transducer means for changing reciprocal motion of said plunger into another motion; a barrel; a coupling member; means by which said barrel is journaled to said housing; means removably afiixing said coupling member to said barrel so that movement of the barrel releases the coupling member;

said barrel being connected to said plunger by said transducer whereby reciprocation of said plunger by said support means causes movement of said barrel to thereby release said coupling member.

2. Apparatus of claim 1 wherein said transducer includes a grooved cam, means rotatably mounting said grooved cam within said housing, a portion of said plunger forming part of said transducer, said plunger having means associated therewith which cooperate with the grooves of said grooved cam. whereby reciprocation of the plunger causes rotation of said grooved cam.

3. The apparatus of claim 1 and further including a second transducer for converting the motion of said transducer into rotational motion of a higher torque; said second transducer being interposed between said barrel and the first said transucer.

4. Release mechanism as defined in claim 1 wherein said transducer includes a grooved cam means rotatably captured within said housing;

' said grooves being disposed about the outer peripheral surface of said grooved cam with the groove extending in a downward direction for a limited disstance longitudinally of said housing whereupon said groove reverses direction and continues back up the cam at an acute angle with respect to the longitudinal axis ofthe housing, with the groove continuing until terminating in another vertical groove identical to the first said vertical groove;

a downwardly depending skirt member forming a part of said plunger and having a plurality of spaced apart steel balls captured therein and inwardly protruding from the inside peripheral surface of said skirt member, one said steel ball adapted to ride within the groove of said grooved cam to thereby enable reciprocal motion of said plunger to cause the cam to rotate.

5. Apparatus as defined in the foregoing claim 4, wherein said grooved cam has a jack-screw attached thereto;

a mandrel slidably received within said barrel, means preventing relative rotation between said mandrel and said barrel, said jack-screw adapted to be threadedly received within a portion of said mandrel whereby rotation of said grooved cam causes said mandrel to move longitudinally of said housing.

6. The apparatus defined in claim 5 wherein said mandrel has means forming a slot and a groove therein, said slot receiving a stop means therein, a pin, said pin being spaced apart from said grooved cam and said mandrel when said cable release mechanism is in the fully unreleased configuration.

7. Apparatus as defined in claim 1 and further including biasing means for urging said plunger in a downward direction;

spaced apart groove contacting means connected to said plunger;

:1 grooved cam having means forming a groove about a surface thereof with said groove continuing about said cam in a manner which forms a continuous grooved path about said cam;

said groove contacting means adapted to ride in said groove so as to present a force which causes said cam to rotate in one direction when said plunger is reciprocated;

a mandrel, a jack-screw, said jack-screw being afiixed to said grooved cam, said jack-screw threadedly engaging said mandrel, means forming a splined connection between said barrel and said mandrel, whereby:

said jack-screw lifts said mandrel into abutment with said grooved camafter which said mandrel imparts rotational motion into said barrel.

8. Apparatus for controllably releasing objects comprising a housing, a plunger, a transducer, a barrel, and a coupling member;

said coupling member adapted to be attached to the object to be released, means by which said coupling member is releasably attached to said barrel;

means by which a portion of said barrel is rotatably attached to said housing;

means by which a portion of said plunger is reciprocatingly attached to said housing, means by which the apparatus is supported by said plunger;

said transducer interconnecting said plunger and said barrel, said transducer having means by which reciprocal motion of said plunger is changed into rotary motion at said barrel; whereby:

reciprocal motion of said plunger causes said coupling to be released from said barrel.

9. Apparatus of claim 8 wherein said transducer includes a grooved cam, means rotatably mounting said grooved cam within said housing, a portion of said plunger forming part of said transducer, said plunger having means associated therewith which cooperate with the grooves of said grooved carn whereby reciprocation of the plunger causes rotation of said grooved cam.

10. Release mechanism as defined in claim 8 wherein said transducer includes a grooved cam means rotatably captured within said housing;

said grooves being disposed about the outer peripheral surface of said grooved cam with the groove extending in a downward direction for a limited distance longitudinally of said housing whereupon said groove reverses direction and continues back up the cam at an acute angle with respect to the longitudinal axis of the housing, with the groove continuing until terminating in another vertical groove identical to the first said vertical groove;

2. downwardly depending skirt member forming a part of said plunger and having a plurality of spaced apart steel balls captured therein and inwardly protruding from the inside peripheral surface of said skirt member, one said steel ball adapted to ride within the groove of said grooved cam to thereby enable reciprocal motion of said plunger to cause the cam to rotate.

References Cited UNITED STATES PATENTS DONALD A. GRIFFIN, Primary Examiner U.S. Cl. X.R. 

